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The crystal structure of [1.1.1]propellane at 138 K
Author(s) -
Seiler Paul
Publication year - 1990
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19900730603
Subject(s) - chemistry , propellane , crystallography , molecule , crystal (programming language) , crystal structure , phase transition , symmetry (geometry) , group (periodic table) , phase (matter) , x ray crystallography , diffraction , stereochemistry , bicyclic molecule , condensed matter physics , organic chemistry , geometry , optics , physics , mathematics , computer science , programming language
The molecular structure of [1.1.1]propellane has been determined from single‐crystal X‐ray diffraction measurements at 138 K. The crystals of this reactive compound were grown from the melt at ca. 263 K. The space group is C 2, and the asymmetric unit contains four molecules. All have large thermal motion and two show orientational disorder as well. Because of these problems, the atomic positions cannot be determined with high accuracy. Within the experimental limits, the two ordered molecules have D 3h symmetry, with corrected lengths of central and side bonds of ca. 1.60 Å and 1.53 Å, respectively. At lower temperature, the crystals undergo a phase transition. The transition temperature, in the range of 100 to 132 K, varied from one crystal sample to another. All crystals obtained of the low‐temperature phase were twinned, and its space group could not be established.